Internet access is being restricted in Iran as violent protests sparked by the death of a woman in police custody spread across the country, according to residents and global internet watchdog NetBlocks.
Last week's death of 22-year-old Mahsa Amini, who was arrested by morality police in Tehran for "unsuitable attire", unleashed anger over issues including freedoms in the Islamic republic and an economy reeling from sanctions.
Kurdish rights group Hengaw said 10 protesters had been killed as a result of "direct fire" from government forces in the last four days and 450 people had been injured in the Kurdish regions of Iran alone.
Amnesty International said it had so far managed to confirm eight of those deaths, including a 16-year-old boy shot dead when security forces opened fire on protesters.
"At least two other people have lost sight in one or both eyes," Amnesty reported, adding that security forces had used metal pellets, tear gas, water cannons and beatings with batons to disperse protesters.
"Hundreds more, including children, have sustained painful injuries amounting to torture or other ill-treatment due to the unlawful use of birdshot and other munitions against them."
With protests now taking place in more than 50 cities and towns, Iranian authorities have restricted communications, making it difficult to organise protests and share information.
NetBlocks director of research Isik Mater said WhatsApp was the first platform to be targeted on Wednesday, followed shortly after by Instagram, curbing the last remaining social media and messaging apps permitted in Iran.
"This was followed within hours by a widespread internet shutdown with high impact to mobile networks," Ms Mater told the ABC.
"The restrictions will continue to create additional barriers to communications within Iran and with the outside world."
Meta Platforms, the owner of Instagram and WhatsApp, did not immediately respond to a request for comment.
Ms Amini, who was from the Kurdish city of Saqez, was visiting the capital Tehran with her family when she was arrested by morality police.
She collapsed after being taken to a detention centre to be "educated", and died in hospital three days later.
Her father said she had no health problems and she suffered bruises to her legs during her time in custody.
He holds the police responsible for her death. The police have denied harming her.
Protesters burn hijabs, chant 'death to the dictator'
After beginning on Saturday at Ms Amini's funeral in the Kurdish region, protests have engulfed much of the country, prompting confrontations as security forces have sought to suppress them.
Iranian law requires women to cover their hair with a hijab and their arms and legs with loose clothing.
Women have waved and burnt their hijabs or headscarves during the protests, with some cutting their hair in public.
Videos of Wednesday's unrest posted online showed protesters in Tehran chanting: "No to the headscarf, no to the turban, yes to freedom and equality!"
Other videos shared on social media have shown demonstrators damaging symbols of the Islamic republic and confronting security forces.
One shows a man scaling the facade of the town hall in the northern city of Sari and tearing down an image of Ayatollah Ruhollah Khomeini, who founded the Islamic republic after the 1979 revolution.
Another shows hundreds of people shouting "death to the dictator" at Tehran University.
The ABC could not verify the authenticity of the videos.
State media and officials have depicted the unrest as riots carried out by "anti-revolutionary elements".
Members of the Basij, a militia under the umbrella of Iran's Revolutionary Guards, held their own rallies in Tehran on Wednesday.
"The morality police is just an excuse, what they target is the regime itself," they chanted in a video posted on 1500tasvir.
Zainab Hosseni from Melbourne's Iranian Women's Association said it was not surprising demonstrators were clashing with police.
"This is just a natural response to years and years of deprivation," she said.
"The community in Iran, 70 per cent of the population is under the age of 30. People want freedom, people want basic rights."
Global rallies support Iran protests
Demonstrations of solidarity have taken place across the world including Turkey, Canada, Sweden, Italy, the Netherlands and cities across the United States.
In New York, demonstrators placed images of dead political prisoners on the ground in front of the United Nations headquarters.
Speaking to the UN General Assembly on Wednesday, US President Joe Biden said: "Today we stand with the brave citizens and the brave women of Iran, who right now are demonstrating to secure their basic rights."
Mr Biden also explicitly called out human rights abuses by China, Burma and the Taliban in his remarks, saying: "The United States will always promote human rights and the values enshrined in the UN charter in our own country and around the world."
The UN commissioner for human rights called for an impartial investigation into Ms Amini's death and allegations of torture and ill-treatment.
A top aide to Supreme Leader Ayatollah Ali Khamenei gave his condolences to Ms Amini's family this week, promising to follow up on the case and saying the leader was pained by her death.
